The compound (7.alpha.,17.alpha.)-17-hydroxy-7-methyl-19-nor-17-pregn-5(10)-en-20-yn-3- one having the structural formula 1:
is known, for example from U.S. Pat. No(s). 3,340,279 and 4,701,450. The method described in these patents leads to a compound having combined oestrogenic, progestagenic and androgenic characteristics. This compound is used in medicaments having gonadomimetic, ovulation-inhibiting or immuno-modulating action.
Surprisingly, it has now been found that the compound having the formula 1. prepared in accordance with the method described in the abovementioned patents, is polymorphous and consists of two crystalline pure forms.